/*
 * Copyright (C) 2009 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#ifndef PINYINIME_ANDPY_INCLUDE_LPICACHE_H__
#define PINYINIME_ANDPY_INCLUDE_LPICACHE_H__

#include <stdlib.h>
#include "./searchutility.h"
#include "./spellingtrie.h"

namespace ime_pinyin {

    // Used to cache LmaPsbItem list for half spelling ids.
    class LpiCache {
        private:
            static LpiCache *instance_;
            static const int kMaxLpiCachePerId = 15;

            LmaPsbItem *lpi_cache_;
            uint16 *lpi_cache_len_;

        public:
            LpiCache();
            ~LpiCache();

            static LpiCache &get_instance();

            // Test if the LPI list of the given splid  has been cached.
            // If splid is a full spelling id, it returns false, because we only cache
            // list for half ids.
            bool is_cached ( uint16 splid );

            // Put LPI list to cahce. If the length of the list, lpi_num, is longer than
            // the cache buffer. the list will be truncated, and function returns the
            // maximum length of the cache buffer.
            // Note: splid must be a half id, and lpi_items must be not NULL. The
            // caller of this function should guarantee this.
            Size_t put_cache ( uint16 splid, LmaPsbItem lpi_items[], Size_t lpi_num );

            // Get the cached list for the given half id.
            // Return the length of the cached buffer.
            // Note: splid must be a half id, and lpi_items must be not NULL. The
            // caller of this function should guarantee this.
            Size_t get_cache ( uint16 splid, LmaPsbItem lpi_items[], Size_t lpi_max );
    };

}  // namespace

#endif  // PINYINIME_ANDPY_INCLUDE_LPICACHE_H__
